1,274 research outputs found

    Robotic automation in computer controlled polishing

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    We first present a Case Study – the manufacture of 1.4 m prototype mirror-segments for the European Extremely Large Telescope, undertaken by the National Facility for Ultra Precision Surfaces, at the OpTIC facility operated by Glyndwr University. Scale-up to serial-manufacture demands delivery of a 1.4 m off-axis aspheric hexagonal segment with surface precision < 10 nm RMS every four days, compared with a typical year or more for an one-off part. This requires a radically-new approach to large optics fabrication, which will inevitably propagate into wider industrial optics. We report on how these ambitious requirements have stimulated an investigation into the synergy between robots and computer numerically controlled (‘CNC’) polishing machines for optical fabrication. The objective was not to assess which is superior. Rather, it was to understand for the first time their complementary properties, leading us to operate them together as a unit, integrated in hardware and software. Three key areas are reported. First is the novel use of robots to automate currently-manual operations on CNC polishing machines, to improve work-throughput, mitigate risk of damage to parts, and reduce dependence on highly-skilled staff. Second is the use of robots to pre-process surfaces prior to CNC polishing, to reduce total process time. The third draws the threads together, describing our vision of the automated manufacturing cell, where the operator interacts at cell rather than machine level. This promises to deliver a step-change in end-to-end manufacturing times and costs, compared with either platform used on its own or, indeed, the state-of-the-art used elsewhere

    The role of robotics in computer controlled polishing of large and small optics

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    Following formal acceptance by ESO of three 1.4m hexagonal off-axis prototype mirror segments, one circular segment, and certification of our optical test facility, we turn our attention to the challenge of segment mass-production. In this paper, we focus on the role of industrial robots, highlighting complementarity with Zeeko CNC polishing machines, and presenting results using robots to provide intermediate processing between CNC grinding and polishing. We also describe the marriage of robots and Zeeko machines to automate currently manual operations; steps towards our ultimate vision of fully autonomous manufacturing cells, with impact throughout the optical manufacturing community and beyond

    'I would rather die': reasons given by 16-year-olds for not continuing their study of mathematics

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    Improving participation rates in specialist mathematics after the subject ceases to be compulsory at age 16 is part of government policy in England. This article provides independent and recent support for earlier findings concerning reasons for non- participation, based on free response and closed items in a questionnaire with a sample of over 1500 students in 17 schools, close to the moment of choice. The analysis supports findings that perceived difficulty and lack of confidence are important reasons for students not continuing with mathematics, and that perceived dislike and boredom, and lack of relevance, are also factors. There is a close relationship between reasons for non-participation and predicted grade, and a weaker relation to gender. An analysis of the effects of schools, demonstrates that enjoyment is the main factor differentiating schools with high and low participation indices. Building on discussion of these findings, ways of improving participation are briefly suggested

    Effect of magnetic state on the Îłâˆ’Î±\gamma -\alpha transition in iron: First-principle calculations of the Bain transformation path

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    Energetics of the fcc (γ\gamma) - bcc (α\alpha) lattice transformation by the Bain tetragonal deformation is calculated for both magnetically ordered and paramagnetic (disordered local moment) states of iron. The first-principle computational results manifest a relevance of the magnetic order in a scenario of the γ\gamma - α\alpha transition and reveal a special role of the Curie temperature of α\alpha-Fe, TCT_C, where a character of the transformation is changed. At a cooling down to the temperatures T<TCT < T_C one can expect that the transformation is developed as a lattice instability whereas for T>TCT > T_C it follows a standard mechanism of creation and growth of an embryo of the new phase. It explains a closeness of TCT_C to the temperature of start of the martensitic transformation, MsM_s.Comment: 4 pages, 3 figures, submitted in Phys. Rev. Letter

    Contacting the spirits of the dead: paranormal belief and the teenage worldview

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    A number of previous studies have examined both the overall level of belief expressed by young people in the paranormal and the major demographic predictors of such belief. Building on this research tradition, the present study examines how one specific paranormal belief concerning contact with the spirits of the dead integrates with the wider teenage worldview. Data provided by 33,982 pupils age 13 to 15 years throughout England and Wales demonstrated that almost one in three young people (31%) believed that it is possible to contact the spirits of the dead. Compared with young people who did not share this belief, the young people who believed in the possibility of contacting the spirits of the dead displayed lower psychological wellbeing, higher anxiety, greater isolation, greater alienation, less positive social attitudes, and less socially conforming lifestyles. Overall, paranormal beliefs seem to be associated with a less healthy worldview, in both personal and social terms

    Mathematical stories: Why do more boys than girls choose to study mathematics at AS-level in England?

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    Copyright @ 2005 Taylor & FrancisIn this paper I address the question: How is it that people come to choose mathematics and in what ways is this process gendered? I draw on the findings of a qualitative research study involving interviews with 43 young people all studying mathematics in post-compulsory education in England. Working within a post-structuralist framework, I argue that gender is a project and one that is achieved in interaction with others. Through a detailed reading of Toni and Claudia’s stories I explore the tensions for young women who are engaging in mathematics, something that is discursively inscribed as masculine, while (understandably) being invested in producing themselves as female. I conclude by arguing that seeing ‘doing mathematics’ as ‘doing masculinity’ is a productive way of understanding why mathematics is so male dominated and by looking at the implications of this understanding for gender and mathematics reform work.This work is funded by the ESR

    Underground tales, overground lives: mobile work identities through to post-retirement

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    Although there has been recent attention given to the subject of mobile work, there has been less focus, within mobility studies, on the work of those who enable movement: the job of the transport worker. This article takes this incarnation of mobile workers as the basis for understanding the ways in which mobile work identities are pulled through into retirement. The article firstly proposes that transport workers, as movement enablers, have particular identities, and are an important and neglected topic of study within mobilities. Secondly, it suggests that the post-work identities of mobile workers are contingent on their experiences during their working lives and that these are particular to mobile work. The article is evidenced through data gathered during a mobile ethnographic study with two retired London Underground employees. The participants joined the researchers on a walking tour of a disused underground railway station in London, ‘Hidden London’, organised by the London Transport Museum and their experiences and emotional responses were recorded and analysed. Understanding post-work identities through the embodied and spatial experiences of the present, the research sought insights of the past and future; the continuity and fluidity of working identities that permeated through to post-work lives. This article argues that mobile work identities are specific identities that shape a distinct post-retirement identity
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